Singer 66 Side clamp attachments
These are from 1923, 1929 and 1941. By 1945 Singer had changed the standard assortment, removing the tucker and cloth guide and adding the edger and gather foot.
For 23-41 the standard set came 6 attachments - Foot Hemmer (for hemming and felling) Adjustable Hemmer, Binder, Tucker, Ruffler (2 slot), cloth guide with screw. They also came with two screwdrivers, large for the machine and a small one for adjusting the tension on the bobbin case.
The Darning plate is the only "optional" accessory listed in the manual of this age group.
The far left set is my collection of black side attachments
The Adjustable Hemmer - the early version required you to remove the lower part, the later version was changed so you could loosen it and swing it out of the way.
The lower left shows the base foot with the guide removed. Lower right shows the screw loosened and the guide swung out of the way.
Above both shows the difference in the base - notice the notch compared to the one on the right. Also, the screw on the newer version was not meant to be removed (but you can if you really try).
Another difference is the location of the two rivets on the guide - older style has them both on the side end, newer style has them towards the top.
And for fun, some of the black side combinations -even the rivets.
This is the piece (and the large screwdriver) that you will most commonly find partially black - even if the rest of the attachments in the set are nickel. I have more black of this newer style than nickel.